Printing collet construction



Dec. 29, 1959 D. c. KILLARY ET AL 2,918,867

I PRINTING COLLET CONSTRUCTION Filed June 26. 1956 I 1' 7 14 5 51 4 mm /5 l I I a a v l t m1; c genr Wit A ATTORNEY United States Patent 2,918,867 PRINTING COLLET CONSTRUCTION David Charles Killary, Cranford, N.J., and Frederick Henry Wittel, Charlotte, N.C.

Application June 26, 1956, Serial No. 593,914 1' Claim. (Cl. 101-375) The present invention relates to a collet, and it particularly relates to a collet for printing cylinders.

In manufacturing printing cylinders it is customary to make the cylinder and shaft all in one piece, which clearly increases the weight in the bulk and involves not only considerable storage problems, since special racks, receptacles and storage bins must be provided to carry both the cylinders and the substantially and unitarily assembled shafts, but furthermore, a considerable weight of metal is tied up involving a tremendous capital expenditure.

Because" of the weight involved and the handling difficulties, considerable time is consumed and substant al labor charges are involved in mounting and dismantling the cylinders from printing presses, and in operations preparatory to printing, such as plating, engraving or mounting printing plates.

In existing demountable cylinders which use heating procedures and hot shrinking connections to attach and detach a cylinder from the shaft, in contrast to the permanent joint type construction, these heating procedures frequently take considerable time and often can result in off circular displacement of the cylinder. Any side to side adjustment of the cylinder on the shaft requires repeating the heating procedures requiring further loss of time and tedious adjustments.

In existing demountable cylinders where set screw adjustments are utilized, the set screw adjustment is difficult where proper concentricity is to be achieved and, moreover, the set screws will vibrate, flex, work loose and are difiicult to tighten.

Th'ese assemblies of shafts and cylinders, even with hot shrinking processes or set screw procedures produce cylinder combinations in which the rotational speed is limited because of the tendency towards vibration and oscillation due to lack of a solid joint or union between cylinder and shaft. Other more complicated mechanical cylinder locking devices are expensive, heavy, inaccurate, and protrude too far outside of the cylinder and are timeconsuming to mount.

Furthermore, the one piece integral permanent shaft cylinders when stored, due to the projecting shaft ends, tend to be damaged, particularly at the projecting end portions thereof, and are particularly difiicult to stack and store.

It is therefore among the objects of the present invention to provide a superior simplified printing cylinder construction in which the printing cylinder will be most conveniently assembled with the shaft without shrinking or set screw assembly procedure, and with a minimum of time required and greatly reduced labor charges and with assurance that the assembly when made will always substantially automatically produce a thor- 2,918,867 Patented Dec. 29, 1959 2 oughly concentric printing surface without extended adjustment or centering procedures.

Another object is to provide a printing cylinder stor-'- age and supply system in which the weight of the cylinders may be reduced and the cylinders may be stored independently of their shafts with the shaft and cylinder being readily and quickly assembled to achieve true con;

centricity without set screw adjustment procedures and hot sweating procedures.

A further object is to provide a novel cylinder shaft assembly which may be quickly mounted and located in position and also quickly dismounted with rapid adjustment on the press and without likelihood of any maladjustment as occurs with set screw procedures where the set screws loosen and break off.

A still further object of the present invention is to provide a faster running cylinder shaft combination in which the cylinder will be substantially tightly held on to the shaft and will maintain its concentricity and correct printing position even through high web speeds of 500 feet per minute to 1000 feet per minute are employed.

Still further objects and advantages will appear in the more detailed description set forth below, it being uriderstood, however, that this more detailed description is" given by way of illustration and explanation only and not by way of limitation, since various changes therein may be made by those skilled in the art without departing from the scope and spirit of the present invention.

In accomplishing the above objects it has been found most satisfactory to provide plug ends for the printing cylinders, which plug ends are mounted permanently as" a part ofthe cylinder end and which will have a standard internal diameter or recessed conical opening to receive a readily applied beveled collet to which the present in vention is most particularly directed.

In the preferred form of the beveled collet, three elements are employed, one element consisting of a" tapered slotted and split spring steel or tool steel tapered ring or shell which is held in position on a threaded collar or base by means of a split or resilient retaining ring.

To give the conical portion of the collet the desired flexibility a plurality of spaced longitudinal slots are cutinto the body terminating however short of the front and rear ends thereof without extending all the way there through.

At one side of the collet and parallel to these slots is one through slot which splits the collet and serves to' enable the collet to be taken up and tightly jammed upon the shaft.

As a general rule the plug which receives the collet has an interiorly inwardly tapered portion to receive and jam the collet inwardly and an exteriorly threaded or tapped recess which receives the threaded collar of the collet.

With the foregoing and other objects in view the invention consists of the novel construction, combination and arrangement of parts as hereinafter more specifically described, and illustrated in the accompanying drawings, wherein is shown an embodiment of the invention, but it is to be understood that changes, variations and modi fications can be resorted to which fall within the scope of the claim hereunto appended.

In the drawings wherein like reference characters dc note corresponding parts throughout the several views:

Fig. 1 is a transverse end sectional view showing the Fig. 2 is an exploded view of the collet perspective showing the manner of its assembly.

Referring particularly to Fig. 2, the sleeve D is tapered in the direction and it has a relatively thin forward inwardly directed end 11 and a relatively thick rear end 12 which terminates in the short flange 13 forming the shoulder 14.

Around the periphery there are a plurality of spaced slots 15 which terminate short of the end faces 16 and 17, the slot being longer and extending into the flange adjacent the rear end 12 as indicated at 18 in Fig. 1.

At the thin end the slot also terminates along a bevel as indicated at 19 in Fig. 1. It will therefore be noted by reference to Fig. 1 that the slot is of minimum length adjacent the internal periphery at 20 and of maximum length 21 adjacent the outside face of the tapered sleeve One of the slots goes all the way through as indicated at 22 so that the interior of the sleeve D may be squeezed together to grip the shaft G and hold the printing cylinder A tightly in position thereon.

The split ring E consists of a steel member which is slotted at 3% so that it may be inserted in the recess 31 in the base F, and so that it will bear against the face or shoulder 14 of the flange 13.

The internal periphery 32 has such a diameter that it will always clear the thick portion 12 of the tapered sleeve D, as shown best in Fig. l.

he base or driving head F itself has an outside threaded portion 33 with a recess 34 into which the flange portion I3 is inserted. The outer portion of the recess 34 is beveled at 35 and has a transverse slot 36. The outside face 37 has the spaced recesses 38 to receive the yoke of a tightening tool and enable the collect to be tightened into the plug B.

The plug B will be of varying diameters depending upon the internal diameter of the cylinder A. The plug B is shrunk or otherwise heat attached at 45 to the end 46 of the printing cylinder A. It has a beveled contact face 47 for the tapered outside face 23 of the sleeve D.

It also has the threaded recess 48 which receives the threaded portion 33 of the base F.

As shown, by using collets with different internal diameters, the collet arrangement may be utilized upon shaft diameters ranging from 1 /2 inches to 3 inches and with cylinder dimensions ranging from 3 inches to 20 inches in diameter.

A wide variety of different types of printing cylinders, whether of the aniline type, or rotogravure, may be employed and the end plugs may be shrunk or welded in position.

The taper of the collet sleeve D may vary from 10 to 15 degrees and the not through slots will soften its gripping action in combination with the through slot.

The collet sleeve itself may be of spring steel or tool steel or other alloy, and desirably the base of the collet has a rolled thread.

Although the collet is separate from the cylinder and end plug the final mounting will give a more dependable and solid union therewith than with shrunk or set screw or other mechanical connections.

Even though high speeds of 500 feet to 1000 feet per minute at the periphery are employed it is found that there is maintained an accuracy of less than /2 of 1000ths of an inch in concentricity over long working periods.

The cylinders may be quickly mounted or removed and can be adjusted on the press without being taken off the press. This contrasts greatly to heating expansion systems which take 15 minutes to a half hour, or the old set screw adjustments which in spite of the care given vibrate, flex and work loose and cannot be adjusted right in the press.

Furthermore, since the collets are inexpensive to manufacture and do not tie up any substantial amount of metal or machinery, they may be readily left in the cylinders as end protections without necessarily requiring the shaft to be left at position and will protect the cylinders against being burred, dented or otherwise damaged on the critical internal diameters.

The collets may be produced inexpensively and are most readily tightened in position in seconds as compared to prior practices in the printing industries.

The present dismountable collet type printing cylinder is superior to one piece integrally mounted shafted cylinders and many other types of dismountable cylinders.

In the present invention the collet D and the driving head F operate independently although they are kept in assembly by the retaining ring E.

This retaining ring E has two projecting ears 30a which enable it to be decreased in diameter when it is inserted in the recess in the interior face of the driving head F.

Whereas a solid one piece collet, as for example if D and E were made integral or rigid, would necessarily have to rotate upon entrance into the internal diameter of the plug B, and when it was tightened such integral construction would have a tendency to scrape the internal diameter of the plug B and the external diameter of the shaft G.

This would result in burs and small pieces of metal being picked up and would prevent the achievement of a uniform and concentric hand tight union.

in the present invention the driving head F may be tightened into the plug B without rotation of the tapered member D so that such formation of burs and scraping do not occur.

The retaining ring E will hold the tapered member D and the driving head F in permanent assembly while permitting relative rotation between them.

Upon Withdrawing the tapered member D the ring E will retain the tapered member D and the driving head F together.

This retaining ring E assures a free floating action which allows the tapered member D to be forced into position and drawn out of position in a straight plane without rotation.

It is readily possible to change the arrangement of the slots 15 shown in the tapered member D so that there may be a larger or smaller member and so that they may also be inclined to the longitudinal diameter of the union.

While there has herein been illustrated and described the preferred embodiments of the invention, it is to be understood that applicants do not limit themselves to the precise construction herein disclosed, and the right is reserved to all changes and modifications coming within the scope of the invention as defined in the appended claim.

Having now particularly described and ascertained the nature of the invention, and in what manner the same is to be performed, what is claimed is:

A collet construction for a demountable printing cylinder of the type having a cylindrical printing element upon a central axial shaft extending longitudinally therethrough, said construction including an end plug permanently heat attached in the end of the cylinder having a threaded recess with an intermediate shoulder at the bottom of the recess and a tapered hole extending from said shoulder to the inside face of the plug with its smaller diameter at said inside face, an externally threaded annular driving head, having a recess on its inside face, attached to said plug by cooperation of the threads on said driving head and said plug, a longitudinally tapered sleeve having a short flange at one end and a plurality of partial longitudinally extending slots equally spaced about the periphery of the tapered portion of said sleeve and in the flanged portion thereof and terminating short of the tapered end of said sleeve, and also having a through slit at one side through the entire length of said portion and said flange forming a split sleeve, and a split rin holding said flange in position in said recess of said 196,149 driving head, and said tapered sleeve being force fitted 574,077 in said tapered hole and being clamped against said shaft 1,253,594 to hold said cylinder on said shaft. 1,995,973 5 2,587,606 References Cited in the file of this patent UNITED STATES PATENTS 4,280

165,546 Cook July 13, 1875 587,076

Hope Oct. 16, 1877 Sellers Dec. 29, 1896 Hasty Jan. 15, 1918 Ericksson Mar. 26, 1935 Dungler Mar. 4, 1952 FOREIGN PATENTS Great Britain Dec. 12, 1874 Great Britain Apr. 14, 1947 

